(a) Field of the Invention
The present invention provides a cup sleeve formed with a reverse damping structure having one or more rings inwardly bent and annularly arranged on one or both of the edge and the inner periphery of the cup sleeve, so when the mentioned cup sleeve is sleeved with a cup-shaped or bottle-shaped or can-shaped container, the anti-slip damping for enhancing the anti-loose function is provided by the reverse damping structure, thus the cup sleeve is less likely to be released from the cup-shaped or bottle-shaped or can-shaped container, and with the reverse damping structure, the interval formed between the cup sleeve and the cup-shaped or bottle-shaped or can-shaped container is enlarged thereby increasing the thermal insulation effect.
(b) Description of the Prior Art
A conventional thermal insulation cup sleeve is usually formed in parallel or formed with a ring shape having larger caliber at the top and smaller caliber at the bottom, for being sleeved with a cup-shaped or bottle-shaped or can-shaped container; because the inner caliber of the cup sleeve has to be larger than the diameter of the cup-shaped or bottle-shaped or can-shaped container for being sleeved in, the cup sleep may be more likely to slip or fall after being sleeved with the cup-shaped or bottle-shaped or can-shaped container; if a cup sleeve made of a paper material is used to be directly in contact with the cup-shaped or bottle-shaped or can-shaped container, the provided thermal insulation effect is relatively reduced; if a cup sleeve made of a corrugated board having tubular hole layers is adopted, the thermal insulation effect is increased but still has a disadvantage of being likely to slip and fall.